This invention relates to a recording and/or reproducing apparatus for a magneto-optical disc. Specifically, this invention relates to a recording and/or reproducing apparatus for a magneto-optical disc, which is provided with a magnetic head for supplying external magnetic field to the magneto-optical disc.
In a recording apparatus for magneto-optical disc for carrying out recording of information with respect to the magneto-optical disc, there is required a magnetic head for supplying external magnetic field to the magneto-optical disc caused to be in contact with or become close to the surface of the opposite side of laser beam irradiation surface of the magneto-optical disc.
The magnetic head is spaced from the magneto-optical disc at the time except for the time of recording of the magneto-optical disc, and is caused to be in contact with or become close to the magneto-optical disc only at the time of recording. For this reason, it is necessary to move the magnetic head between the recording position caused to be in contact with or become close to the magneto-optical disc and the non-recording position spaced from the magneto-optical disc.
In the prior art, as mechanism for moving the magnetic head for the above-described object, there is provided a mechanism as shown in FIG. 1.
At a top plate of holder (not shown) for holding disc cartridge adapted so that magneto-optical disc is rotatably accommodated within cartridge case which is a square flat casing and moved between fitting position at which this disc cartridge is fitted at a predetermined disc fitting portion and the eject position at which insertion/withdrawal of the disc cartridge is carried out, there is formed a large hole for facing the upper surface of the disc cartridge toward the upper portion.
As shown in FIG. 1, a magnetic head unit 101 is connected to optical pick-up (not shown) through a connection member 106, and is adapted so that it is moved in left and right directions, i.e., in the direction indicated by arrow A in FIG. 1 together with the optical pick-up.
The magnetic head unit 101 is provided at the front end side thereof with a head supporting arm 103 which supports a magnetic head 102 and an arm supporting plate 104 for regulating excessive displacement of this head supporting arm 103.
The head supporting arm 103 is formed by punching thin metal plate having elasticity, e.g., phosphor bronze, etc. The arm supporting plate 104 is adapted so that a front end portion 105 bent L-shaped supports the lower surface of the front end side of the head supporting arm 103, and bottom end portions of this arm supporting plate 104 and the head supporting arm 103 are both fixed and supported at the upper end portion of the channel-shaped connection member 106.
The magnetic head 102 is upwardly and downwardly moved by a head shift plate 107. The head shift plate 107 takes substantially square plate shape, wherein the back end portion is rotatably supported also in both upper and lower directions in the vicinity of the back end portion of the hole of the holder.
At the head shift plate 107, a driven piece 108 is provided in a projected manner (hereinafter simply referred to as projected as occasion may demand) at one side edge and a spring contact piece 109 is projected at the other side edge.
A return spring 110 consisting of plate spring material is adapted so that one end is fixed at the top plate of the holder and the other end is caused to be in contact with the spring contact piece 109 of the head sift plate 107 from the upper side to downwardly bias the head shift plate 107. The driven piece 108 of the head shift plate 107 is positioned at the upper side of a cam piece 112 of a head vertical movement lever 111 rotatably supported at the top plate of the holder. This cam piece 112 is adapted so that falling portion is formed at the back end portion and rising portion is formed at the front end portion and the portion between these falling and rising portions is connected by slating side portion. The state shown in FIG. 1 indicates the state where the driven piece 108 is mounted on the falling portion of the cam piece 112. In this state, the head shift plate 107 is rotated downwardly. As a result, there results the state where the magnetic head unit 101 is downwardly rotated and the magnetic head 102 is in contact with the magneto-optical disc 1 supported by the holder.
At chassis (not shown) on which the holder is supported, a vertical movement control plate 113 is movably supported in forward and backward directions, i.e., in the direction indicated by arrow B (forward direction) and in the direction indicated by arrow C (backward direction) in the figure. At the vertical movement control plate 113, a rack 114 is formed, and this rack 114 is fed by a pinion 116 rotated by a motor 115 so that it is moved in forward and backward directions. At the vertical movement control plate 113, a connection hole 117 is formed at the back end portion, and a connection piece 118 vertically provided at the other end portion of the head vertical movement lever 111 is inserted through the connection hole 117.
Accordingly, when the vertical movement control plate 113 is moved in the forward direction, i.e., in the direction indicated by arrow B in FIG. 1, the head vertical movement lever 111 is rotated in counterclockwise direction, i.e., in the direction indicated by arrow D in FIG. 1. In addition, when the vertical movement control plate 113 is moved in backward direction, i.e., in the direction indicated by arrow C in FIG. 1, the head vertical movement lever 111 is rotated in the clockwise direction, i.e., in the direction indicated by arrow E in FIG. 1.
As described above, the state shown in FIG. 1 is the state at the time of recording, and the vertical movement control plate 113 is placed in the state where it is moved in the direction indicated by arrow C. Thus, the head vertical movement lever 111 is rotated in the clockwise direction, i.e., in the direction indicated by arrow E and the magnetic head 102 is placed in the state where it is positioned lowermost with respect to the holder. In this state, the magnetic head 102 is in contact with the magneto-optical disc 1.
When recording is completed, the vertical movement control plate 113 is moved in the forward direction, i.e., in the direction indicated by arrow B. Thus, the head vertical movement lever 111 is moved in counterclockwise direction, i.e., in the direction indicated by arrow D. As a result, the cam piece 112 is moved in the backward direction and the driven piece 108 of the head shift plate 107 is placed in the state positioned at rising portion of the cam piece 112. Thus, the head shift plate 107 is rotated in the supper direction, and the arm supporting plate 104 and the head supporting arm 103 are lifted by this head shift plate 107 in such a manner that they are rotated in upper direction. As a result, the magnetic head 102 is spaced from the magneto-optical disc 1.
In the above-described conventional recording apparatus for magneto-optical disc, the head vertical movement lever 111 is interposed between the vertical movement control plate 113 and the head shift plate 107 for the purpose of rotating the head shift plate 107. Thus, the number of parts is large and the connecting portions become many. As a result, in the above-described configuration, there are the problems that there results increased cost, positional accuracy of the connecting portions is difficult to be ensured, transmission efficiency of force is poor and reliability is low. Further, in the recording apparatus for magneto-optical disc shown in FIG. 1, there was the problem that members for transmission of force such as vertical movement control plate 113 extending over substantially in forward and backward directions of chassis, connection piece 118 of head vertical movement lever 111 extending upwardly and downwardly at one side portion and head vertical movement plate 111 extending in left and right directions at the upper surface of the holder must be crept over a long distance, so these members take extra space and there is anxiety in arrangement of other members, etc.
In view of the above, an object of this invention is to provide a recording and/or reproducing apparatus for magneto-optical disc which can realize reduction in cost and improvement in reliability by decrease in the number of parts and simplicity of the mechanism, and increase in space merit.
A recording and/or reproducing apparatus for magneto-optical disc according to this invention proposed in order to attain the object as described above includes a body unit, a holder, a magnetic head, a head supporting mechanism and a movement mechanism. The body unit includes a rotation drive portion for rotationally driving at least magneto-optical disc, and an optical pick-up for irradiating laser beams onto the magneto-optical disc rotated by the rotation drive portion. The holder is moved between upper position at which the magneto-optical disc is inserted and lower position at which the inserted magneto-optical disc is held to fit it at the rotation drive portion. The magnetic head supplies external magnetic field to the magneto-optical disc. The head movement mechanism includes a supporting member disposed above the holder in such a manner to oppose the optical pick-up, and provided at one end side with the magnetic head to move this supporting member between recording position at which the magnetic head supplies external magnetic field to the magneto-optical disc held by the holder and non-recording position above the recording position and at which the magnetic head is spaced with respect to the magneto-optical disc. The movement mechanism includes a movement member movably disposed at the side surface of the body unit so that it is moved between a first position at which the head supporting mechanism is driven at the time of recording with respect to the magneto-optical disc to move the magnetic head to the recording position and second position at which the head supporting mechanism is driven at the time of reproduction of the magneto-optical disc to move the magnetic head to the non-recording position.
Further, the recording and/or reproducing apparatus for magneto-optical disc according to this invention includes a body unit, a holder, a magnetic head, a head supporting mechanism and a movement mechanism. The body unit includes a rotation drive portion for rotationally driving at least magneto-optical disc, and an optical pickup for irradiating laser beams onto the magneto-optical disc rotated by the rotation drive portion. The holder is rotatably provided with respect to the body unit between upper position at which the magneto-optical disc is inserted and lower position at which the inserted magneto-optical disc is held to fit it at the rotation drive portion. The magnetic head supplies external magnetic field to the magneto-optical disc. The head supporting mechanism includes a supporting member disposed above the holder in such a manner to oppose the optical pick-up and provided at one end side with the magnetic head to move this supporting member between recording position at which the magnetic head supplies external magnetic field to the magneto-optical disc held by the holder and non-recording position above the recording position and at which the magnetic head is spaced with respect to the magneto-optical disc.
The movement mechanism includes a movement member movably disposed at the side surface of the body unit so that it is moved between first position at which the head supporting mechanism is driven at the time of recording with respect to the magneto-optical disc to move the magnetic head to recording position and second position at which the head supporting mechanism is driven when the holder is moved toward the upper position to move the magnetic head to non-recording position.
Still further objects of this invention and more practical merits obtained by this invention will become more apparent from the description of the embodiment which will be explained.